1. Field of the Invention
The present invention relates to a method for changing a rating code with a macro function key and a receiving apparatus having a function for blocking out a program which can easily change a preset rating code for blocking out the program with the macro to function key.
2. Description of the Prior Art
As children and youngsters increasingly imitate misbehavior and violence learnt from television programs or films and some of them in fact commit crimes, many parents have worried about these phenomena. Whereas a rating system for films has prevented young viewers from watching improper ones, there has been no effective system for television programs.
In the United States, thanks to a recently passed federal regulation, every television set must adopt a discretionary control feature, that is more commonly called a "V-chip" function, that blocks out the outputs of video and audio programs when parents classify a program as improper for their children. Under the regulation, television sets sold in the U.S. market must contain this function by Jan. 1, 2000 (effective as from Jan. 1, 2000).
Various prior arts relating to a discretionary control feature, that is a "V-chip" function, are disclosed in U.S. Pat. Nos. 4,554,584; 4,605,964; 4,888,796; 4,930,158; 4,930,160; 5,172,111; 5,195,135; 5,270,822; 5,387,942; 5,485,518; 5,550,575; 5,583,576; 5,569,366; and 5,737,479.
The blocking-out operation for a television program is carried out as follows. A broadcasting station transmits a television signal including an encoded rating signal on line 21 of the 525 horizontal lines. A receiving circuit of a television set extracts and decodes the encoded rating signal on horizontal line 21, to check whether a rating of the decoded program is within or not within a scope of a preset rating by users, or parents. When the program rating is not within the scope of the preset rating, the outputs of video, audio and text data are blocked out, so that the program can not be viewed. On the contrary, when the program rating is within the scope of the preset rating, the program is allowed to be viewed.
In the system with the "V-chip" function, it takes two or three seconds just after the channel change for decoding the rating code from the received television signal of a changed channel and for initiating the blocking-out operation. By repetitively changing the channel, the viewer can watch any television program since the television program of each of switched channels whose rating is not within the scope of the preset rating cannot be blocked out for two or three seconds and the viewer can view the television program of each channel. To get rid of this blank just after the channel change in the blocking-out operation, it is worth adopting a method which unconditionally blocks out the output of the television program till the rating signal is perfectly decoded. However, this method has a problem that blocks out television program even within the scope of the preset rating.
However, to achieve the above described blocking out function, the user has to set the rating code. Accordingly, there is an inconvenience that the user has to select a rating code control mode, input password, and control the rating code with reference to a rating code guide whenever the user changes the rating code.